Other Operating Income, Net - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Component of Other Operating Income and Expense [Line Items]
Other operating income and expenses, net	$ 59.8	$ 9.1	$ 18.2
Gains on sales of investment land	73.0	3.1	39.3
Asset and portfolio rationalization charge			18.8
Gain (loss) related to litigation settlement			7.7
Gain (loss) on sale of properties			$ 25.3
Reversal of accruals for sales tax and unclaimed property contingencies		$ 6.9
Land
Component of Other Operating Income and Expense [Line Items]
Gains on sales of investment land	69.9
Land \| Austin, Texas and Riverside, California
Component of Other Operating Income and Expense [Line Items]
Gains on sales of investment land	69.9
Net cash proceeds from asset sales	$ 122.8

Component of other operating income and expense.

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- Definition

Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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- Definition

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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- Definition

Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

+ References

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The net amount of other operating income and expenses, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operations.

+ References

No definition available.

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- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

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- Definition

Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan and expenses resulting from the write-down of assets. Excludes expenses related to a business combination, a discontinued operation or an asset retirement obligation.

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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